You might also consider the 70-300L. I prefer the twist zoom over the push/pull of the 100-400 as well as the lighter weight. I have the 400mm 5.6 for when I need the extra reach. I don't find the lack of IS to be a problem as I usually use it at high shutter speeds.

So many nice lenses to choose from.......I'm gonna have to just buy one and then buy more later!!

Hahaha...that's the spirit

I'm guessing you're not married right?

The 70-300L is a real beauty of a lens. I love mine. If you can get closer to the action it would certainly do the job. But if you are further away you may miss the reach a little. Especially if you go full frame later. But as you said...lots of lovely choice out there.